This work examined the surface texture depth profile effects on
apparent viscosity reduction and normal force production for Reh ¼
3:09104 12:1 in the absence of cavitation. Of particular focus is
bidirectional velocity with depth profiles that are fore-aft asymmetric,
and a calibrated experimental setup to avoid misinterpretations of
shear stress reduction (gap offset error) and normal force production
(parallelism error).